P0049Turbocharger/Supercharger A Turbine Overspeed
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- The control module has detected that turbocharger A runs above its permitted maximum speed. Engines equipped for it measure turbine speed with a dedicated sensor on the shaft; while the fault is active some systems continue with an estimated speed and reduce power. Real overspeed arises when too much exhaust energy reaches the turbine, for example because the wastegate or the turbine vanes stick closed, or because the turbocharger has to compensate for a charge-air leak or high altitude. Since a damaged turbocharger can fail completely, the cause should be found before driving on. Turbocharger B has its own code.
- What you may notice
- Check engine light on
- Reduced power or limp mode
- Whistling from the turbocharger
- Risk of turbocharger damage
- Likely causes
- PossibleWastegate or turbine vanes stuck closed, boost control fails
- PossibleTurbocharger speed sensor or its wiring faulty
- RareCharge-air leak forcing the turbocharger to higher speed
- RareEngine control module or software
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €150 – €4,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.